Flat-plate type capillary structure and plate heat pipe having the same

ABSTRACT

A plate heat pipe includes a hollow housing formed in a plate shape and a flat-plate type capillary structure. The flat-plate type capillary structure includes a capillary boundary part and a plurality of primary capillary transportation parts; wherein the capillary boundary part is surroundingly arranged at the periphery of a vaporization portion of the plate heat pipe, and a hollow vapor flowing zone is defined between the capillary boundary part and the vaporization portion. Each of the primary capillary transportation parts is disposed in the vapor flowing zone and extended from the capillary boundary part to the vaporization portion so as to be respectively gathered on the vaporization portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thinned plate heat pipe, especially to a flat-plate type capillary structure and a plate heat pipe having the capillary structure.

2. Description of Related Art

The main trend for developing electronic product is to be thinner, smaller and lighter, so a heat pipe installed therein and used for dissipating or transferring heat is also required to be thinner. For example, an ultra-thin plate heat pipe has a thickness smaller than 1.5 mm.

However, the thickness of the ultra-thin plate heat pipe is thinned, the thickness of a capillary structure installed therein has to be thinner and narrower or there may not be enough space inside the heat pipe for forming gas channels, and because of the capillary structure being thinned, the returning amount of working fluid is also reduced, so it is hard to have enough space inside the plate heat pipe for the installation of any supporting structure. As such, in the ultra-thin plate heat pipe, the capillary structure is also served as a supporting structure.

According to the above-mentioned disadvantages, the distribution of the capillary structure inside the plate heat pipe is unable to be comprehensively designed, and a vapor channel zone and the capillary structure disposed in the plate heat pipe cannot individually provide its best performance. For example, the capillary structure is unable to be provided with a sufficient vaporization surface area, a sufficient condensing surface area and a sufficient liquid transporting cross area, and the interior of the plate heat pipe is unable to provide a sufficient space for the vapor channel zone, and an internal supporting structure having a better structural strength is unable to be provided, so a recessing problem is very likely to happen to the plate heat pipe and an issue of having larger contact thermal resistance is caused, thus the heat transferring efficiency cannot be further enhanced or performed.

In view of the above, the applicant of the present invention has devoted himself for improving the mentioned disadvantages, thus the present invention having a novel design and capable of effectively improving the above-mentioned disadvantages is provided.

SUMMARY OF THE INVENTION

The present invention is to provide a flat-plate type capillary structure and a plate heat pipe having the capillary structure. The flat-plate type capillary structure is able to be effectively distributed in a vapor flowing zone of the plate heat pipe, a liquid-state working fluid is enabled to be returned to a vaporization portion in a most effective manner, and the vapor flowing zone is provided with a sufficient pace for allowing the vaporized working fluid to be transported towards an edge for condensing, so the capillary structure is provided with a better heat transferring efficiency under the situation of the plate heat pipe being thinned.

Accordingly, the present invention provides a flat-plate type capillary structure including: a capillary boundary part and a plurality of primary capillary transportation parts; wherein the capillary boundary part is surroundingly arranged at the periphery of a vaporization portion of the plate heat pipe, and a hollow vapor flowing zone is defined between the capillary boundary part and the vaporization portion. Each of the primary capillary transportation parts is disposed in the vapor flowing zone and extended from the capillary boundary part to the vaporization portion so as to be respectively gathered on the vaporization portion.

Accordingly, the present invention provides a plate heat pipe including a hollow housing formed in a plate shape and the above-mentioned flat-plate type capillary structure disposed in the housing to support a top and a bottom inner walls of the housing.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a perspective view showing the capillary structure according to a first embodiment of the present invention;

FIG. 2 is an enlarged view showing the zone A of FIG. 1;

FIG. 3 is an enlarged view showing the zone B of FIG. 1;

FIG. 4 is a perspective exploded view showing the plate heat pipe according to the first embodiment of the present invention;

FIG. 5 is a perspective view showing the assembly of the plate heat pipe according to the first embodiment of the present invention;

FIG. 6 is a perspective view showing the assembly of the plate heat pipe according to a second embodiment of the present invention;

FIG. 7 is a cross sectional view of FIG. 6 taken alone 7-7;

FIG. 8 is a perspective view showing the assembly of the plate heat pipe according to a third embodiment of the present invention;

FIG. 9 is a perspective exploded view showing the capillary structure according to a fourth embodiment of the present invention;

FIG. 10 is a perspective view showing the assembly of the plate heat pipe according to the fourth embodiment of the present invention;

FIG. 11 is a perspective view showing the assembly of the plate heat pipe according to a fifth embodiment of the present invention; and

FIG. 12 is a partial cross sectional view showing the plate heat pipe according to a sixth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention will be described with reference to the drawings.

Please refer to FIG. 1, FIG. 4 and FIG. 5, wherein FIG. 1 is a perspective view showing the capillary structure according to a first embodiment of the present invention; FIG. 4 is a perspective exploded view showing the plate heat pipe according to the first embodiment of the present invention; and FIG. 5 is a perspective view showing the assembly of the plate heat pipe according to the first embodiment of the present invention. A plate heat pipe of the present invention includes a hollow housing 2 formed in a plate shape, and a flat-plate type capillary structure 1 of the present invention is formed in a flat plate shape and disposed in the housing 2 to support a top and a bottom inner walls of the housing 2.

Please refer to FIG. 1, FIG. 2 and FIG. 3, the capillary structure 1 is formed through sintering fibers, fabrics or metal powders, or a combination of the above, thereby forming a flat-plate shaped member. The capillary structure 1 is disposed in the housing 2, and formed with a capillary vaporization part 10 corresponding to a vaporization portion (i.e. a heating portion) of the plate heat pipe, and a capillary boundary part 11 surroundingly formed at the periphery of the capillary vaporization part 10. A hollow vapor flowing zone 100 is defined between the capillary vaporization part 10 and the capillary boundary part 11. The capillary structure 1 is further formed with a plurality of primary capillary transportation parts 12 arranged in the vapor flowing zone 100 and extended from the capillary boundary part 11 to connect the capillary vaporization part 10, thereby forming a main transportation passage allowing a working fluid to be returned. In addition, the capillary vaporization part 10 is formed with a plurality of heat transferring holes 101 for enhancing the heat transferring effect. Moreover, the thickness of each of the primary capillary transportation parts 12 can be greater than that of the capillary vaporization part 10, and the thickness of each of the primary capillary transportation parts 12 is equal to that of the capillary boundary part 11, and a plurality of gas channels 110 are formed on the capillary boundary part 11 and arranged at intervals, each of the gas channels 110 is formed as being communicated from the outer edge to the inner edge of the capillary boundary part 11 so as to be communicated with the vapor flowing zone 100.

For increasing the return transporting amount of the working fluid being collected towards the capillary vaporization part 10, between the primary capillary transportation parts 12 there can be further formed with a plurality of secondary capillary transportation parts 13 having different lengths and a plurality of auxiliary capillary transportation parts 130, which are all extended from the capillary boundary part 11 towards the capillary vaporization part 10 but not connect to the capillary vaporization part 10, thereby being distributed in the vapor flowing zone 100. The thickness of the secondary capillary transportation part 13 and the thickness of the auxiliary capillary transportation part 130 can be equal to or smaller than that of each of the primary capillary transportation parts 12, and the length of the secondary capillary transportation part 13 is longer than that of the auxiliary capillary transportation part 130.

Please refer to FIG. 4 and FIG. 5, the housing 2 includes a base 20 and a top cover 21 engaged with the base 20 to form the plate shape, the thickness of the housing 2 is smaller than 0.6 mm, and when the capillary structure 1 is disposed in the housing 2 and in contact with a top and a bottom inner walls of the housing 2, a distance d is formed between the outer edge of the capillary boundary part 11 of the capillary structure 1 and a lateral inner wall of the housing 2, so after the vaporized working fluid is transported from the vapor flowing zone 100 towards the capillary boundary part 11, the working fluid is enabled to be further transported to the outer edge of the capillary structure 1 through each of the gas channels 110 for condensing, and the condensed working fluid in a liquid state is then returned to the capillary vaporization part 10 from the capillary boundary part 11 through each of the primary capillary transportation parts 12. According to this embodiment provided by the present invention, a lateral side of the housing 2 is installed with a gas discharging pipe 22 for allowing the plate heat pipe to be processed with an operation of gas filling or discharging, the gas discharging pipe 22 is sealed after the mentioned operation is finished.

As shown in FIG. 6 and FIG. 7, for enabling the liquid-state working fluid to be rapidly transported through each of the primary capillary transportation parts 12 for return, each of the primary capillary transportation parts 12 is laterally extended with a capillary transportation surface 120 having a thinner thickness, and the capillary transportation surface 120 is served to enlarge the surface area defined between the capillary structure 1 and the vapor flowing zone 100, thereby allowing the vapor flowing resistance to be lowered and the capillary surface area for the working fluid being returned to the capillary structure 1 to be enlarged under the situation of maintaining the existence of the vapor flowing zone 100, so an excellent heat exchanging effect can be provided by the thinned plate heat pipe.

As shown in FIG. 8, for increasing the strength among the primary capillary transportation parts 12, the secondary capillary transportation parts 13 and the auxiliary capillary transportation parts 130 so as to simplify the production, a connection rib 121 is provided between two adjacent primary capillary transportation parts 12, two adjacent secondary capillary transportation parts 13 or two adjacent auxiliary capillary transportation parts 130 for the purpose of lateral connection to increase the structural strength and meanwhile assist the transportation of the liquid-state working fluid.

As shown in FIG. 9 and FIG. 10, the capillary vaporization part 10 can also be made of a woven net, sintering powders or sintering fibers, and disposed at a front end 120 of each of the primary capillary transportation parts 12 through a sintering or adhering process.

In addition, as shown in FIG. 11, the capillary structure 1 does not require the installation of the capillary vaporization part 10; in other words, the capillary structure 1 is used for allowing a vaporization portion (i.e. the heating portion of the heat pipe) to transfer heat, so the capillary boundary part 11 is surroundingly arranged at the periphery of the vaporization portion, and the vapor flowing zone 100 is formed between the capillary boundary part 11 and the vaporization portion, each of the primary capillary transportation parts 12 is extended from the capillary boundary part 11 to the vaporization portion for being respectively gathered thereon. According to the present invention, each of the primary capillary transportation parts 12 is able to allow the working fluid to be smoothly returned, and the vapor flowing zone 100 is provided with a sufficient space, so the vapor flowing zone 100 has enough space for being installed with a plurality of flat supporting structures 102.

What shall be addressed is that: as shown in FIG. 12, the inner wall of the housing 2 can be further formed with a plurality of grooves 23 surrounding the capillary structure 1 and partially connected to the capillary structure 1, and the depth of the groove 23 is smaller than 0.03 mm and usually smaller than 30% of the wall thickness of the housing 2, so the structure thereof is very compact, and the grooves 23 being formed on the inner wall of the housing 2 do not affect the vapor flowing zone 100 being formed. The grooves 23 allow the working fluid to be collected on the capillary structure 1 due to surrounding the capillary structure 1 and partially connected to the capillary structure 1. As such, the grooves 23 can be used for assisting the capillary structure 1 so as to work with the capillary structure 1 for forming a capillary transportation network which completely covers the inner wall of the housing 2. In addition, the grooves 23 can be used for condensing in a large scale in the condensing zone, and the condensed working fluid is enabled to be returned to the capillary structure 1 thereby reducing the condensing thermal resistance; and the capillary structure 1 in the vaporizing zone is able to utilize the grooves 23 to allow the vaporization area of the heated working fluid to be enlarged thereby reducing the vaporizing thermal resistance; and the condensed working fluid can be prevented from being formed as tiny water drops adhered on the inner wall of the housing 2 and unable to be returned, so interfering the vapor flow is avoided thereby reducing the thermal resistance of vapor channel; meanwhile, the thermal resistance of the plate heat pipe in the vaporizing zone, the condensing zone and the vapor flowing zone 100 can be effectively reduced.

Moreover, beside being completely formed on the inner wall of the housing 2, the grooves 23 can also be formed at a partial portion of the inner wall of the housing 2, and the grooves 23 can utilize the vaporization portion as the center for being expanded in a concentric or helical direction (e.g. right helical, left helical or both of left and right helical) to the capillary boundary part 11 so as to be formed on the inner wall of the housing 2, the grooves 23 can also be formed in an irregular shape.

Although the present invention has been described with reference to the foregoing preferred embodiment, it will be understood that the invention is not limited to the details thereof.

Various equivalent variations and modifications can still occur to those skilled in this art in view of the teachings of the present invention. Thus, all such variations and equivalent modifications are also embraced within the scope of the invention as defined in the appended claims. 

What is claimed is:
 1. A flat-plate type capillary structure, including: a capillary boundary part, surroundingly arranged at the periphery of a vaporization portion of a plate heat pipe, wherein a hollow vapor flowing zone is defined between the capillary boundary part and the vaporization portion; and a plurality of primary capillary transportation parts, disposed in the vapor flowing zone and extended from the capillary boundary part to the vaporization portion so as to be respectively gathered on the vaporization portion.
 2. The flat-plate type capillary structure according to claim 1, further including a capillary vaporization part disposed on the vaporization portion, wherein the primary capillary transportation parts are respectively connected to the capillary vaporization part.
 3. The flat-plate type capillary structure according to claim 2, wherein the capillary vaporization part is made of a woven net, sintering powders or sintering fibers, and disposed at a front end of each of the primary capillary transportation parts.
 4. The flat-plate type capillary structure according to claim 2, wherein the capillary vaporization part is formed with a plurality of heat transferring holes.
 5. The flat-plate type capillary structure according to claim 2, wherein the thickness of each of the primary capillary transportation parts is greater than that of the capillary vaporization part, and the thickness of each of the primary capillary transportation parts is equal to that of the capillary boundary part.
 6. The flat-plate type capillary structure according to claim 1, wherein a plurality of gas channels are formed on the capillary boundary part and arranged at intervals, and each of the gas channels is formed as being communicated from the outer edge to the inner edge of the capillary boundary part so as to be communicated with the vapor flowing zone.
 7. The flat-plate type capillary structure according to claim 2, wherein a plurality of secondary capillary transportation parts are formed between the primary capillary transportation parts, and the secondary capillary transportation parts are extended from the capillary boundary part towards the capillary vaporization part but not connected to the capillary vaporization part.
 8. The flat-plate type capillary structure according to claim 7, wherein a plurality of auxiliary capillary transportation parts are formed between the primary capillary transportation parts, the auxiliary capillary transportation parts are extended from the capillary boundary part towards the capillary vaporization part but not connected to the capillary vaporization part, and the length of the secondary capillary transportation part is longer than that of the auxiliary capillary transportation part.
 9. The flat-plate type capillary structure according to claim 8, wherein the thickness of the secondary capillary transportation part and the thickness of the auxiliary capillary transportation part are equal to or smaller than that of the primary capillary transportation parts.
 10. The flat-plate type capillary structure according to claim 9, wherein a connection rib is provided between two adjacent primary capillary transportation parts, two adjacent secondary capillary transportation parts or two adjacent auxiliary capillary transportation parts for the purpose of lateral connection.
 11. The flat-plate type capillary structure according to claim 2, wherein each of the primary capillary transportation parts is laterally extended with a capillary transportation surface having a thinner thickness.
 12. The flat-plate type capillary structure according to claim 2, wherein the vapor flowing zone is installed with a plurality of flat supporting structures.
 13. A plate heat pipe, including: a hollow housing, formed in a plate shape; and a flat-plate type capillary, disposed in the housing to support a top and a bottom inner walls of the housing, wherein flat-plate type capillary includes: a capillary boundary part, surroundingly arranged at the periphery of a vaporization portion of a plate heat pipe, wherein a hollow vapor flowing zone is defined between the capillary boundary part and the vaporization portion; and a plurality of primary capillary transportation parts, disposed in the vapor flowing zone and extended from the capillary boundary part to the vaporization portion so as to be respectively gathered on the vaporization portion.
 14. The plate heat pipe having the flat-plate type capillary structure according to claim 13, wherein the housing includes a base and a top cover engaged to the base to form a plate shape.
 15. The plate heat pipe having the flat-plate type capillary structure according to claim 13, wherein a distance is formed between the outer edge of the capillary boundary part of the capillary structure and a lateral inner wall of the housing.
 16. The plate heat pipe having the flat-plate type capillary structure according to claim 13, wherein the inner wall of the housing is formed with a plurality of grooves surrounding the capillary structure and partially connected to the capillary structure, and the depth of the groove is smaller than 30% of the wall thickness of the housing.
 17. The plate heat pipe having the flat-plate type capillary structure according to claim 16, wherein the depth of the groove is smaller than 0.03 mm. 